We propose to extend our use of microtechniques on individual human mammary tumors to the analysis of the enzymatic components of cyclic AMP metabolism. The microchemical technique utilized in this lab enabled microdissection of proportions of histologically confirmed neoplastic cells with ducts and heavily invaded stroma for ultimate use in enzymatic assays. We will demonstrate the usefulness of the technique as both a possible diagnostic tool and as a method for identifying enzymes associated specifically with tumor cells in vivo. We will show the diagnostic potential of the technique by assaying enzymes in tissues of the size taken in needle biopsy. These same tissues will be shown to retain their enzymatic profile under our conditions of long-term storage, offering the capability for re-examining the specimens as a patient shows progress during a particular treatment regimen. We are following the tumor cell-specific activities of adenylate cyclase, cyclic AMP-phosphodiesterase, and 5' AMP-nucleotidase, three enzymes capable of regulating the levels of cyclic AMP and 5'AMP. We are characterizing those enzymes or isozymes which are localized in tumor cells by linking the microtechnique to large scale enzyme purification methods. If during the fractionation procedure more than one form of the enzyme becomes apparent, we will identify which form corresponds to the enzyme which was localized in the tumor cell. To identify the fraction which is localized, we will utilize additional microtechniques. We can, thus, match an enzyme or isozyme activity obtained by the large scale fractionation to its location within a group of cancer cells and then characterize that fraction for clues as to its mode of regulation in vivo.